Recurring air in radiators, pressure down

[Susanne]

I'm a newbie to handymanship, and thought I'd ask this question here, before getting a plumber in:

I have a problem with needing to bleed my radiators (run by a Vaillant boiler) every 2 months or so, and consequently having to refill the system to bring the pressure back up.

Is there anything I myself can check/tighten to try to retify the problem, before getting a plumber in, or is it impossible to say without looking at the job? (ie. are there common problem-areas that I could have a look at, or could it be anywhere in the system)

Also, I need to balance our system, as one radiator (the lowest one) never gets hot - I kind of have an idea of how to do this, but I think it'll take a long time, and I won't do this until it's warmer in the weather now, as I don't want my young kids to be cold in the house - but could a balancing problem ever cause air intake or pressure issues?

Many thanks in advance for your time,
Susanne

 

[bengasman]

What is the pressure when fully cold before you decide to top up?
Frequent filling means you are low on inhibitor so you will find almost surely corrosion and limescale in your system.
Do something about that now, as leaving it will cost you dearly in the future.

 

[Susanne]

Thanks, how do I add inhibitor?

Can I just check:


This house was done up in year 2000, to a modern standard, and I assume they would have redone the pipes, as everything we can see (in the loft and basement) looks new.

When I bleed the radiators, I get completely clear water, the only thing is that when bleeding the radiators, a slightly smelly air comes out the radiator before the water fills up.

The boiler is a Vaillant EcoMax, and was installed new ca. 2003 before we moved in.

If I have rusty pipes, would the water not be brown and smelly (as I remember it being in my parents house, which was v. old)?

How often do I have to add inhibitor?
Can I add too much?

Thanks again.

 

[Susanne]

Sorry, forgot to say:

I'm not sure how low the pressure is when fully cold, but when hot it's just under/on the green area on the bar-scale, ie. at ca. half a bar.

I've just been up to check it, and it was at half a bar again, inspite filling it up to 2 bar only two or three weeks ago, just before christmas.
If the pressure is down, I guess I need to bleed again, but haven't checked...


Does recurrent air mean a leak in the system?
If not, where's the water that put the pressure up to 2 before Christmas?


Many thanks again,
Susanne